Generally, the total amount of cash contributions you can deduct is limited to 50% of your adjusted gross income (AGI) shown on line 38 of Form 1040. If you’re a high-income earner, your contributions and other itemized deductions may be limited if your AGI exceeds a certain dollar amount. This is in addition to the 50% limit for contributions.
In certain situations, your deduction may be limited to 30% or 20%. Credit Karma Tax doesn’t support these limitations.